This invention relates to a distributed storage system.
Systems in which generated data are held in a large number of edge nodes to be used in analysis are expected to become popular with the arrival of the IoT era. A system of this type is demanded to back up a large amount of data in edge nodes with few resources.
For example, an asynchronous remote copy technology is disclosed in U.S. Pat. No. 7,152,079 B2 (PTL1). Configurations disclosed therein include the following:
“A first storage system stores information relating to the updating of data stored in that system as a journal. More specifically, the journal is includes a copy of data that was used for updating and update information such as a write command used during updating. Furthermore, the second storage system acquires the journal via a communication line between the first storage system and the second storage system. The second storage system holds a duplicate of the data held by the first storage system and updates the data corresponding to the data of the first storage system in the data update order of the first storage system by using the journal.” (Abstract).
The asynchronous remote copy technology described above is capable of preventing the latency of host I/O from increasing, by transferring data to be backed up to a remote data center asynchronously with host I/O.